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Magnetic shielding design analysis (open access)

Magnetic shielding design analysis

Two passive magnetic-shielding-design approaches for static external fields are reviewed. The first approach uses the shielding solutions for spheres and cylinders while the second approach requires solving Maxwell's equations. Experimental data taken at LLNL are compared with the results from these shieldings-design methods, and improvements are recommended for the second method. Design considerations are discussed here along with the importance of material gaps in the shield.
Date: December 27, 1983
Creator: Kerns, J.A.; LaPaz, A.D. & Fabyan, J.
System: The UNT Digital Library
Some illustrations of stochasticity (open access)

Some illustrations of stochasticity

A complex, and apparently stochastic, character frequently can be seen to occur in the solutions to simple Hamiltonian problems. Such behavior is of interest, and potentially of importance, to designers of particle accelerators--as well as to workers in other fields of physics and related disciplines. Even a slow development of disorder in the motion of particles in a circular accelerator or storage ring could be troublesome, because a practical design requires the beam particles to remain confined in an orderly manner within a narrow beam tube for literally tens of billions of revolutions. The material presented is primarily the result of computer calculations made to investigate the occurrence of ''stochasticity,'' and is organized in a manner similar to that adopted for presentation at a 1974 accelerator conference.
Date: December 27, 1977
Creator: Laslett, L.J.
System: The UNT Digital Library
U-Sr isotopic speedometer: Fluid flow and chemical weatheringrates inaquifers (open access)

U-Sr isotopic speedometer: Fluid flow and chemical weatheringrates inaquifers

Both chemical weathering rates and fluid flow are difficultto measure in natural systems. However, these parameters are critical forunderstanding the hydrochemical evolution of aquifers, predicting thefate and transport of contaminants, and for water resources/water qualityconsiderations. 87Sr/86Sr and (234U/238U) activity ratios are sensitiveindicators of water-rock interaction, and thus provide a means ofquantifying both flow and reactivity. The 87Sr/86Sr values in groundwaters are controlled by the ratio of the dissolution rate to the flowrate. Similarly, the (234U/238U) ratio of natural ground waters is abalance between the flow rate and the dissolution of solids, andalpha-recoil loss of 234U from the solids. By coupling these two isotopesystems it is possible to constrain both the long-term (ca. 100's to1000's of years) flow rate and bulk dissolution rate along the flow path.Previous estimates of the ratio of the dissolution rate to theinfiltration flux from Sr isotopes (87Sr/86Sr) are combined with a modelfor (234U/238U) to constrain the infiltration flux and dissolution ratefor a 70-m deep vadose zone core from Hanford, Washington. The coupledmodel for both (234U/238U) ratios and the 87Sr/86Sr data suggests aninfiltration flux of 5+-2 mm/yr, and bulk silicate dissolution ratesbetween 10-15.7 and 10-16.5 mol/m2/s. The process of alpha-recoilenrichment, while primarily responsible for the observed variation …
Date: December 27, 2005
Creator: Maher, Kate; DePaolo, Donald J. & Christensen, John N.
System: The UNT Digital Library
Nuclear Resonance Fluorescence Excitations Near 2 MeV in 235U and 239Pu (open access)

Nuclear Resonance Fluorescence Excitations Near 2 MeV in 235U and 239Pu

A search for nuclear resonance fluorescence excitations in {sup 235}U and {sup 239}Pu within the energy range of 1.0- to 2.5-MeV was performed using a 4-MeV continuous bremsstrahlung source at the High Voltage Research Laboratory at the Massachusetts Institute of Technology. Measurements utilizing high purity Ge detectors at backward angles identified 9 photopeaks in {sup 235}U and 12 photopeaks in {sup 239}Pu in this energy range. These resonances provide unique signatures that allow the materials to be non-intrusively detected in a variety of environments including fuel cells, waste drums, vehicles and containers. The presence and properties of these states may prove useful in understanding the mechanisms for mixing low-lying collective dipole excitations with other states at low excitations in heavy nuclei.
Date: December 27, 2006
Creator: Bertozzi, W.; Caggiano, J. A.; Hensley, W. K.; Johnson, M. S.; Korbly, S. E.; Ledoux, R. J. et al.
System: The UNT Digital Library
Using pseudo transient continuation and the finite element method to solve the nonlinear Poisson-Boltzmann equation (open access)

Using pseudo transient continuation and the finite element method to solve the nonlinear Poisson-Boltzmann equation

The nonlinear Poisson-Boltzmann (PB) equation is solved using Pseudo Transient Continuation. The PB solver is constructed by modifying the nonlinear diffusion module of a 3D, massively parallel, unstructured-grid, finite element, radiation-hydrodynamics code. The solver also computes the electrostatic energy and evaluates the force on a user-specified contour. Either Dirichlet or mixed boundary conditions are allowed. The latter specifies surface charges, approximates far-field conditions, or linearizes conditions ''regulating'' the surface charge. The code may be run in either Cartesian, cylindrical, or spherical coordinates. The potential and force due to a conical probe interacting with a flat plate is computed and the result compared with direct force measurements by chemical force microscopy.
Date: December 27, 2000
Creator: Shestakov, A I; Milovich, J L & Noy, A
System: The UNT Digital Library
Optimum Vehicle Component Integration with InVeST (Integrated Vehicle Simulation Testbed) (open access)

Optimum Vehicle Component Integration with InVeST (Integrated Vehicle Simulation Testbed)

We have developed an Integrated Vehicle Simulation Testbed (InVeST). InVeST is based on the concept of Co-simulation, and it allows the development of virtual vehicles that can be analyzed and optimized as an overall integrated system. The virtual vehicle is defined by selecting different vehicle components from a component library. Vehicle component models can be written in multiple programming languages running on different computer platforms. At the same time, InVeST provides full protection for proprietary models. Co-simulation is a cost-effective alternative to competing methodologies, such as developing a translator or selecting a single programming language for all vehicle components. InVeST has been recently demonstrated using a transmission model and a transmission controller model. The transmission model was written in SABER and ran on a Sun/Solaris workstation, while the transmission controller was written in MATRIXx and ran on a PC running Windows NT. The demonstration was successfully performed. Future plans include the applicability of Co-simulation and InVeST to analysis and optimization of multiple complex systems, including those of Intelligent Transportation Systems.
Date: December 27, 2001
Creator: Ng, Walter; Paddack, Erma & Aceves, Salvador
System: The UNT Digital Library
TECHNOLOGY DEVELOPMENT AND DEPLOYMENT OF SYSTEMS FOR THE RETRIEVAL AND PROCESSING OF REMOTE-HANDLED SLUDGE FROM HANFORD K-WEST FUEL STORAGE BASIN (open access)

TECHNOLOGY DEVELOPMENT AND DEPLOYMENT OF SYSTEMS FOR THE RETRIEVAL AND PROCESSING OF REMOTE-HANDLED SLUDGE FROM HANFORD K-WEST FUEL STORAGE BASIN

In 2011, significant progress was made in developing and deploying technologies to remove, transport, and interim store remote-handled sludge from the 105-K West Fuel Storage Basin on the Hanford Site in south-central Washington State. The sludge in the 105-K West Basin is an accumulation of degraded spent nuclear fuel and other debris that collected during long-term underwater storage of the spent fuel. In 2010, an innovative, remotely operated retrieval system was used to successfully retrieve over 99.7% of the radioactive sludge from 10 submerged temporary storage containers in the K West Basin. In 2011, a full-scale prototype facility was completed for use in technology development, design qualification testing, and operator training on systems used to retrieve, transport, and store highly radioactive K Basin sludge. In this facility, three separate systems for characterizing, retrieving, pretreating, and processing remote-handled sludge were developed. Two of these systems were successfully deployed in 2011. One of these systems was used to pretreat knockout pot sludge as part of the 105-K West Basin cleanup. Knockout pot sludge contains pieces of degraded uranium fuel ranging in size from 600 {mu}m to 6350 {mu}m mixed with pieces of inert material, such as aluminum wire and graphite, in the …
Date: December 27, 2011
Creator: RE, RAYMOND
System: The UNT Digital Library
Biospecimen Reporting for Improved Study Quality (open access)

Biospecimen Reporting for Improved Study Quality

Human biospecimens are subjected to collection, processing, and storage that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research that uses human tissues, it is crucial that information on the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications on biospecimen-related research and to help reassure patient contributors and the advocacy community that their contributions are valued and respected.
Date: December 27, 2010
Creator: Moore, Ph.D., Helen M.; Kelly, Ph.D., Andrea B.; Jewell, Ph.D., Scott D.; McShane, Ph.D., Lisa M.; Clark, M.D., Douglas P.; Greenspan, M.D., Renata et al.
System: The UNT Digital Library
Ge(Li) low level in-situ gamma-ray spectrometer applications (open access)

Ge(Li) low level in-situ gamma-ray spectrometer applications

Currently a Ge(Li) spectrometer is being employed for in-situ measurements of radionuclides contained in soil. This is being done at nuclear reactor sites and in complex radionuclide fields at the Nevada Test Site. The methodology and precision of the in-situ spectrometric technique was previously established for analysis of radionuclides in soil. Application of the technique to gaseous and liquid effluents containing radionuclides has shown a great deal of promise. (auth)
Date: December 27, 1973
Creator: Phelps, P. L.; Anspaugh, L. R.; Roth, S. J.; Huckabay, G. W. & Sawyer, D. L.
System: The UNT Digital Library
Effect of Flux Adjustments on Temperature Variability in Climate Models (open access)

Effect of Flux Adjustments on Temperature Variability in Climate Models

It has been suggested that ''flux adjustments'' in climate models suppress simulated temperature variability. If true, this might invalidate the conclusion that at least some of observed temperature increases since 1860 are anthropogenic, since this conclusion is based in part on estimates of natural temperature variability derived from flux-adjusted models. We assess variability of surface air temperatures in 17 simulations of internal temperature variability submitted to the Coupled Model Intercomparison Project. By comparing variability in flux-adjusted vs. non-flux adjusted simulations, we find no evidence that flux adjustments suppress temperature variability in climate models; other, largely unknown, factors are much more important in determining simulated temperature variability. Therefore the conclusion that at least some of observed temperature increases are anthropogenic cannot be questioned on the grounds that it is based in part on results of flux-adjusted models. Also, reducing or eliminating flux adjustments would probably do little to improve simulations of temperature variability.
Date: December 27, 1999
Creator: Duffy, P.; Bell, J.; Covey, C. & Sloan, L.
System: The UNT Digital Library
Providing an earthquake-like environment for testing full-scale structures by using the ground motion from underground nuclear tests (open access)

Providing an earthquake-like environment for testing full-scale structures by using the ground motion from underground nuclear tests

None
Date: December 27, 1972
Creator: Bernreuter, D.L. & Tokarz, F.J.
System: The UNT Digital Library
Neutrino flow and the collapse of stellar cores (open access)

Neutrino flow and the collapse of stellar cores

None
Date: December 27, 1974
Creator: Wilson, J. R.
System: The UNT Digital Library
Formation of inner-shell autoionizing CO+ states below the CO++ threshold (open access)

Formation of inner-shell autoionizing CO+ states below the CO++ threshold

We report a kinematically complete experiment on the production of CO{sup +} autoionizing states following photoionization of carbon monoxide below its vertical double ionization threshold. Momentum imaging spectroscopy is used to measure the energies and body-frame angular distributions of both photo- and autoionization electrons, as well as the kinetic energy release (KER) of the atomic ions. This data, in combination with ab initio theoretical calculations, provides insight into the nature of the cation states produced and their subsequent dissociation into autoionizing atomic (O*) fragments.
Date: December 27, 2009
Creator: Osipov, Timur; Weber, Thorsten; Rescigno, Thomas N; Lee, Sun; Orel, Ann; Schoffler, Markus et al.
System: The UNT Digital Library
Comprenhensive Program of Engineering and Geologic Surveys for Designing and Constructing Radioactive Waste Storage Facilities in Hard Rock Massifs (open access)

Comprenhensive Program of Engineering and Geologic Surveys for Designing and Constructing Radioactive Waste Storage Facilities in Hard Rock Massifs

Geological, geophysical, and engineering-geological research conducted at the 'Yeniseisky' site obtained data on climatic, geomorphologic, geological conditions, structure and properties of composing rock, and conditions of underground water recharge and discharge. These results provide sufficient information to make an estimate of the suitability of locating a radioactive waste (R W) underground isolation facility at the Nizhnekansky granitoid massif
Date: December 27, 2002
Creator: Gupalo, T; Milovidov, V; Prokopoca, O & Jardine, L
System: The UNT Digital Library
Self-efficacy mechanism at work: The context of environmental volunteer travel (open access)

Self-efficacy mechanism at work: The context of environmental volunteer travel

This article contributes the first utilization of Bandura’s self-efficacy (SE) mechanism in the context of environmental volunteer travel demonstrating how environmental stewardship, hedonic experience, and environmental SE relate to one another in this particular setting
Date: December 27, 2018
Creator: Strzelecka, Marianna; Woosnam, Kyle M. & Nisbett, Gwendelyn S.
System: The UNT Digital Library
The Arabidopsis PAD4 Lipase-Like Domain Is Sufficient for Resistance to Green Peach Aphid (open access)

The Arabidopsis PAD4 Lipase-Like Domain Is Sufficient for Resistance to Green Peach Aphid

Article exploring PAD4 functions in plant defense by expressing the N-terminal PAD4 lipase-like domain (PAD4ᴸᴸᴰ) without its C-terminal EDS1-PAD4 (EP) domain. The authors show that transgenic expression of PAD4ᴸᴸᴰ in Arabidopsis is sufficient for limiting GPA infestation but not for conferring basal and effector-triggered pathogen immunity. This suggests that the C-terminal PAD4 EP domain is necessary for EDS1-dependent immune functions but is dispensable for aphid resistance. Moreover, PAD4ᴸᴸᴰ is not sufficient to interact with EDS1, indicating the PAD4-EP domain is required for stable heterodimerization. These data provide molecular evidence that PAD4 has domain-specific functions.
Date: December 27, 2019
Creator: Dongus, Joram A.; Bhandari, Deepak D.; Patel, Monika; Archer, Lani; Dijkgraaf, Lucas; Shah, Jyoti et al.
System: The UNT Digital Library
A Symmetric Approach Elucidates Multisensory Information Integration (open access)

A Symmetric Approach Elucidates Multisensory Information Integration

This article shows that the Borsuk-Ulam theorem applies also to multisensory integration: two environmental stimuli from different sensory modalities display similar features when mapped into cortical neurons.
Date: December 27, 2016
Creator: Tozzi, Arturo & Peters, James F.
System: The UNT Digital Library
Computational Fluid Dynamics, potential flow and system-based simulations of fully appended free running 5415M in calm water and waves (open access)

Computational Fluid Dynamics, potential flow and system-based simulations of fully appended free running 5415M in calm water and waves

Article assesses the capabilities of computational fluid dynamics (CFD), potential flow (PF), and system-based (SB) methods for course keeping in calm water and regular and bi-chromatic waves for 5415M as a benchmark test case for AVT-161.
Date: December 27, 2018
Creator: Toxopeus, Serge; Sadat Hosseini, Seyed Hamid; Visonneau, Michel; Guilmineau, Emmanuel; Yen, Tin-Guen; Lin, Woei-Min et al.
System: The UNT Digital Library
The Community Climate System Model: CCSM3 (open access)

The Community Climate System Model: CCSM3

A new version of the Community Climate System Model (CCSM) has been developed and released to the climate community. CCSM3 is a coupled climate model with components representing the atmosphere, ocean, sea ice, and land surface connected by a flux coupler. CCSM3 is designed to produce realistic simulations over a wide range of spatial resolutions, enabling inexpensive simulations lasting several millennia or detailed studies of continental-scale climate change. This paper will show results from the configuration used for climate-change simulations with a T85 grid for atmosphere and land and a 1-degree grid for ocean and sea-ice. The new system incorporates several significant improvements in the scientific formulation. The enhancements in the model physics are designed to reduce or eliminate several systematic biases in the mean climate produced by previous editions of CCSM. These include new treatments of cloud processes, aerosol radiative forcing, land-atmosphere fluxes, ocean mixed-layer processes, and sea-ice dynamics. There are significant improvements in the sea-ice thickness, polar radiation budgets, equatorial sea-surface temperatures, ocean currents, cloud radiative effects, and ENSO teleconnections. CCSM3 can produce stable climate simulations of millenial duration without ad hoc adjustments to the fluxes exchanged among the component models. Nonetheless, there are still systematic biases in …
Date: December 27, 2004
Creator: Collins, W. D.; Blackmon, M.; Bitz, C.; Bonan, G.; Bretherton, C. S.; Carton, J. A. et al.
System: The UNT Digital Library
Charge exchange produced K-shell x-ray emission from Ar16+ in a tokamak plasma with neutral beam injection (open access)

Charge exchange produced K-shell x-ray emission from Ar16+ in a tokamak plasma with neutral beam injection

High-resolution spectroscopy of hot tokamak plasma seeded with argon ions and interacting with an energetic, short-pulse neutral hydrogen beam was used to obtain the first high-resolution K-shell x-ray spectrum formed solely by charge exchange. The observed K-shell emission of Ar{sup 16+} is dominated by the intercombination and forbidden lines, providing clear signatures of charge exchange. Results from an ab initio atomic cascade model provide excellent agreement, validating a semiclassical approach for calculating charge exchange cross sections.
Date: December 27, 2004
Creator: Beiersdorfer, P; Bitter, M; Marion, M & Olson, R E
System: The UNT Digital Library
Will Russian Scientists Go Rogue? A Survey on the Threat and the Impact of Western Assistance (open access)

Will Russian Scientists Go Rogue? A Survey on the Threat and the Impact of Western Assistance

The collapse of the Soviet Union sparked fears throughout the world that rogue nations and terrorist organizations would gain access to weapons of mass destruction (WMD). One specific concern has been 'WMD brain drain.' Russians with knowledge about nuclear, chemical, and biological weapons could now depart to any country of their choice, including rogue nations seeking to produce WMD. Meanwhile, Russian science fell into a protracted crisis, with plummeting salaries, little funding for research, and few new recruits to science. These developments increased both the incentives and the opportunities for scientists to sell their knowledge to governments and terrorist organizations with hostile intentions toward the United States. Recognizing the threat of WMD brain drain from Russia, the United States, and other governments implemented a host of programs designed to reduce the risk. Despite, or perhaps partly because of, massive assistance from the West to prevent scientists with WMD knowledge from emigrating, the threat of Russian WMD brain drain has recently faded from view. Yet we have seen no evidence that these programs are effective and little systematic assessment of the current threat of WMD migration. Our data from an unprecedented survey of 602 Russian physicists, biologists, and chemists suggest that …
Date: December 27, 2004
Creator: Ball, D Y & Gerber, T P
System: The UNT Digital Library
Elevated Concentrations of Primordial Radionuclides in Sediments from the Reedy River and Surrounding Creeks in Simpsonville, South Carolina (open access)

Elevated Concentrations of Primordial Radionuclides in Sediments from the Reedy River and Surrounding Creeks in Simpsonville, South Carolina

A gamma-ray survey and analysis of sixteen riverbed samples from the Reedy River watershed near Simpsonville, SC were conducted and compared with national and international studies of primordial radionuclides. The study reported here follows on a recent discovery of anomalously high uranium concentrations in several private well waters in the area near Simpsonville, SC. A HPGe spectrometer was used for quantification of gamma emitting radionuclides in the sediments. All sediments contained radionuclides from the uranium and thorium series as well as {sup 40}K. Uranium-238 concentrations in sediment samples ranged from 11.1 to 74.2 Bq kg{sup -1}. The measured radionuclide concentrations were compared with data from UNSCEAR and NURE reports. The river and stream sediment data were augmented by in situ NaI(Tl) gamma-ray spectrometer measurements. Comparisons between the ex-situ and in-situ measurements indicate equivalently distributed uranium in the surface soils and stream sediments, the source of which is likely attributed to the monazite belts that are known to exist in the area.
Date: December 27, 2006
Creator: Powell, B. A.; Hughes, L. D.; Soreefan, A. M.; Falta, D.; Wall, M. & DeVol, T. A.
System: The UNT Digital Library
Collisionless coupling of ion and electron temperatures in counter-streaming plasma flows (open access)

Collisionless coupling of ion and electron temperatures in counter-streaming plasma flows

None
Date: December 27, 2012
Creator: Ross, J. S.; Park, H. S.; Berger, D.; Divol, L.; Kugland, N. L.; Rozmus, W. et al.
System: The UNT Digital Library
Effects of longitudinal space charge in beams for heavy-ion fusion (open access)

Effects of longitudinal space charge in beams for heavy-ion fusion

A new analytic model is presented that accurately estimates the radially averaged axial component of the space-charge field of an axisymmetric heavy-ion beam in a cylindrical beam pipe. The model recovers details of the field near the beam ends that are overlooked by simpler models, and the results compare well to exact solutions of Poisson`s equation. Field values are shown for several simple beam profiles and are compared with values obtained from simpler models. The model has been implemented in the fluid/envelope code CIRCE and used to study longitudinal confinement in beams with a variety of axial profiles. The effects of errors in the longitudinal-control fields are presented.
Date: December 27, 1995
Creator: Sharp, W. M.; Friedman, A. & Grote, D. P.
System: The UNT Digital Library